GEOLOGY 201 - MIDTERM 1 EXAM QUESTIONS
WITH VERIFIED ANSWERS
How many cleavage planes (counting parallel sides as one) does the mineral quartz have?
0
How many cleavage planes does amphibole (hornblende) have?
2
How many cleavage planes does augite (pyroxene) have?
2
How many cleavage planes does biotite have?
1
Biotite, amphibole and pyroxene are all darkly colored. In a small sample- such as in a
rock- you probably have to look at the sample through a magnifying hand lens. What are
features you might use to distinguish them?
Number of cleavage planes & Angle between cleavage planes
How many cleavage planes does potassium feldspar (orthoclase feldspar) have?
2
At what angle do the cleavage planes of both the feldspars (orthoclase & plagioclase) come
together?
90
Which mineral has cleavage planes that come together at approximately 60/120:
amphibole
Cleavage planes form best where the mineral has what type of bonding?
ionic
The formula for olivine (the pretty green mineral) is (Mg/Fe)2SiO4. What is meant by the
notation (Mg/Fe)2 in the formula?
It's a free for all - mix and match Mg and Fe as needed!
What condition needs to be met for one ion to substitute for another ion in a mineral
formula?
They must have a similar ionic radius
, What is the overall charge of the silica tetrahedra SiO4?
-4
Which of the following are framework silicates? (Select all that apply)
Quartz, Orthoclase feldspar, Plagioclase feldspar
Which mineral is harder on the Mohs hardness scale? (i.e. which will scratch the other!)
Quartz
An element with differing number of neutrons in the nucleus compared to the number of
protons is called:
Isotope
What are the most common elements in the continental crust?
Silicon and Oxygen
Which mineral class is made up of double chains of silica tetrahedra?
Amphibole
Which mineral has an isolated tetrahedra structure?
Olivine
What is the charge of the Magnesium ion that bonds into the olivine mineral?
+2
Which of the following mineral that we examined in class is not a silicate mineral?
Calcite
Where would you go to find a divergent plate boundary?
A mid-oceanic ridge
A typical rate of plate motion is:
1-10 mm/year
Where would you go to find a convergent plate boundary?
the west coast of South America
Oceanic crust is _________ than continental crust.
thinner
Where would you go to find a transform plate boundary?
on the ocean floor between segments of mid-oceanic ridge
WITH VERIFIED ANSWERS
How many cleavage planes (counting parallel sides as one) does the mineral quartz have?
0
How many cleavage planes does amphibole (hornblende) have?
2
How many cleavage planes does augite (pyroxene) have?
2
How many cleavage planes does biotite have?
1
Biotite, amphibole and pyroxene are all darkly colored. In a small sample- such as in a
rock- you probably have to look at the sample through a magnifying hand lens. What are
features you might use to distinguish them?
Number of cleavage planes & Angle between cleavage planes
How many cleavage planes does potassium feldspar (orthoclase feldspar) have?
2
At what angle do the cleavage planes of both the feldspars (orthoclase & plagioclase) come
together?
90
Which mineral has cleavage planes that come together at approximately 60/120:
amphibole
Cleavage planes form best where the mineral has what type of bonding?
ionic
The formula for olivine (the pretty green mineral) is (Mg/Fe)2SiO4. What is meant by the
notation (Mg/Fe)2 in the formula?
It's a free for all - mix and match Mg and Fe as needed!
What condition needs to be met for one ion to substitute for another ion in a mineral
formula?
They must have a similar ionic radius
, What is the overall charge of the silica tetrahedra SiO4?
-4
Which of the following are framework silicates? (Select all that apply)
Quartz, Orthoclase feldspar, Plagioclase feldspar
Which mineral is harder on the Mohs hardness scale? (i.e. which will scratch the other!)
Quartz
An element with differing number of neutrons in the nucleus compared to the number of
protons is called:
Isotope
What are the most common elements in the continental crust?
Silicon and Oxygen
Which mineral class is made up of double chains of silica tetrahedra?
Amphibole
Which mineral has an isolated tetrahedra structure?
Olivine
What is the charge of the Magnesium ion that bonds into the olivine mineral?
+2
Which of the following mineral that we examined in class is not a silicate mineral?
Calcite
Where would you go to find a divergent plate boundary?
A mid-oceanic ridge
A typical rate of plate motion is:
1-10 mm/year
Where would you go to find a convergent plate boundary?
the west coast of South America
Oceanic crust is _________ than continental crust.
thinner
Where would you go to find a transform plate boundary?
on the ocean floor between segments of mid-oceanic ridge
